So by that same token if A Godzilla Movie has a Giant Iguana with hind legs its still a viable Godzilla film?

Yes. If within the "official" Japanese Godzilla movie productions it is acceptable to have a baby Godzilla the size of an 8 year old Japanese kid dancing around and blowing smoke rings...then I can accept the American version as a "version" of the Godzilla family.

I have seen most if not all "giant critter terrorizing mankind" movies. I have seen all "Godzilla" movies. Some are good, some are bad....but they are all "giant critter terrorizing mankind" or "Godzilla" movies.